Long Island TDEM survey locations

Saltwater intrusion is the most common type of water-quality degradation in coastal-plain aquifers. In coastal areas, the hydraulic head under predevelopment (nonpumping) conditions is higher on land than in the surrounding saltwater embayments; thus, fresh groundwater flows seaward (from areas of high potential to areas of lower potential) and meets saltwater at an equilibrium point (interface)...